It is common practice to study physico-chemical phenomena by a procedure customarily referred to as variational spectroscopy. This approach entails the collection of spectra as some physical parameter is varied—for example, the temperature. Temperature-induced changes in the spectra are then monitored by measuring some spectral parameter, such as band position (or frequency), intensity, or width. Over the years we and others have used this type of measurement extensively to study temperature- and pressure-induced phase transitions of biological membranes. In the course of recent experiments on specifically labeled <sup>13</sup>C=O phospholipids, we came across an unexpected and intriguing example of how one can be misled by a frequency shift.
You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.
Contact your librarian or system administrator
Login to access OSA Member Subscription